/* Copyright    Massachusetts Institute of Technology    1985	*/

/*

Copyright 1985, 1986, 1987 by the Massachusetts Institute of Technology

Permission to use, copy, modify, and distribute this
software and its documentation for any purpose and without
fee is hereby granted, provided that the above copyright
notice appear in all copies and that both that copyright
notice and this permission notice appear in supporting
documentation, and that the name of M.I.T. not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
M.I.T. makes no representations about the suitability of
this software for any purpose.  It is provided "as is"
without express or implied warranty.

*/



/*
Copyright (C) 2001-2025 Free Software Foundation, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at
your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

/*
 * XMenu:	MIT Project Athena, X Window system menu package
 *
 *	XMenuActivate -	Maps a given menu to the display and activates
 *			the menu for user selection.  The user is allowed to
 *			specify which pane and selection will be current,
 *			the X and Y location of the menu (relative to the
 *			parent window) and the mouse button event mask that
 *			will be used to identify a selection request.
 *
 *			A menu selection is shown to be current by placing
 *			a highlight box around the selection as the mouse
 *			cursor enters its active region.  Inactive selections
 *			will not be highlighted.  As the mouse cursor moved
 *			from one menu pane to another menu pane the pane being
 *			entered is raised and made current and the pane being
 *			left is lowered.
 *
 *			Anytime XMenuActivate returns, the p_num and
 *			s_num are left at their last known values (i.e.,
 *			the last known current pane and selection indices).
 *			The following are the defined return states:
 *
 *			1)	If at any time an error occurs the data
 *				pointer is left untouched and XM_FAILURE
 *				is returned.
 *
 *			2)	When a selection request is received (i.e.,
 *				when the specified mouse event occurs) the
 *				data pointer will be set to the data
 *				associated with the particular selection
 *				current at the time of the selection request
 *				and XM_SUCCESS is returned.
 *
 *			3)	If no selection was current at the time a
 *				selection request is made the data pointer
 *				will be left untouched and XM_NO_SELECT will
 *				be returned.
 *
 *			4)	If the selection that was current at the time
 *				a selection request is made is not an active
 *				selection the data pointer will be left
 *				untouched and XM_IA_SELECT will be returned.
 *
 *			Since X processes events in an asynchronous manner
 *			it is likely that XMenuActivate will encounter
 *			a "foreign event" while it is executing.  Foreign
 *			events are handled in one of three ways:
 *
 *			1)	The event is discarded.  This is the default
 *				mode and requires no action on the part of the
 *				application.
 *
 *			2)	The application has identified an asynchronous
 *				event handler that will be called and the
 *				foreign event handed off to it.  Note:
 *				AEQ mode disables this mode temporarily.
 *
 *			3)	The application has enabled asynchronous event
 *				queuing mode.  In this mode all foreign events
 *				will be	queued up until XMenuActivate
 *				terminates; at which time they will be
 *				returned to the	X event queue.  As long as
 *				AEQ mode is enabled any asynchronous event
 *				handler as temporarily disabled.
 *
 *			Any events encountered while taking down the menu
 *			(i.e., exposure events from occluded windows) will
 *			automatically be returned to the X event queue after
 *			XMenuActivate has cleaned the queue of any of its own
 *			events that are no longer needed.
 *
 *	Author:		Tony Della Fera, DEC
 *			March 12, 1986
 *
 */

#include "XMenuInt.h"
#include <X11/keysym.h>

/* For debug, set this to 0 to not grab the keyboard on menu popup */
static int x_menu_grab_keyboard = 1;

static Wait_func wait_func;
static void* wait_data;
static Translate_func translate_func = NULL;

void
XMenuActivateSetWaitFunction (Wait_func func, void *data)
{
  wait_func = func;
  wait_data = data;
}

void
XMenuActivateSetTranslateFunction (Translate_func func)
{
  translate_func = func;
}

int
XMenuActivate(
    register Display *display,		/* Display to put menu on. */
    register XMenu *menu,		/* Menu to activate. */
    int *p_num,				/* Pane number selected. */
    int *s_num,				/* Selection number selected. */
    int x_pos,				/* X coordinate of menu position. */
    int y_pos,				/* Y coordinate of menu position. */
    unsigned int event_mask,		/* Mouse button event mask. */
    char **data,			/* Pointer to return data value. */
    void (*help_callback) (char const *, int, int)) /* Help callback.  */
{
    int status;				/* X routine call status. */
    int orig_x;				/* Upper left menu origin X coord. */
    int orig_y;				/* Upper left menu origin Y coord. */
    int ret_val;			/* Return value. */

    register XMPane *p_ptr;		/* Current XMPane. */
    register XMPane *event_xmp;		/* Event XMPane pointer. */
    register XMPane *cur_p;		/* Current pane. */
    register XMSelect *cur_s;		/* Current selection. */
    XMWindow *event_xmw;		/* Event XMWindow pointer. */
    XEvent event;			/* X input event. */
    XEvent peek_event;			/* X input peek ahead event. */

    Bool selection = False;		/* Selection has been made. */
    Bool forward = True;		/* Moving forward in the pane list. */

    Window root, child;
    int root_x, root_y, win_x, win_y;
    unsigned int mask;
    KeySym keysym;

    /*
     * Define and allocate a foreign event queue to hold events
     * that don't belong to XMenu.  These events are later restored
     * to the X event queue.
     */
    typedef struct _xmeventque {
	XEvent event;
	struct _xmeventque *next;
    } XMEventQue;

    XMEventQue *feq = NULL;    		/* Foreign event queue. */
    XMEventQue *feq_tmp;		/* Foreign event queue temporary. */

    /*
     * If there are no panes in the menu then return failure
     * because the menu is not initialized.
     */
    if (menu->p_count == 0) {
	_XMErrorCode = XME_NOT_INIT;
	return(XM_FAILURE);
    }

    /*
     * Find the desired current pane.
     */
    cur_p = _XMGetPanePtr(menu, *p_num);
    if (cur_p == NULL) {
	return(XM_FAILURE);
    }
    cur_p->activated = cur_p->active;

    /*
     * Find the desired current selection.
     * If the current selection index is out of range a null current selection
     * will be assumed and the cursor will be placed in the current pane
     * header.
     */
    cur_s = _XMGetSelectionPtr(cur_p, *s_num);

    /*
     * Compute origin of menu so that cursor is in
     * Correct pane and selection.
     */
    _XMTransToOrigin(display,
		     menu,
		     cur_p, cur_s,
		     x_pos, y_pos,
		     &orig_x, &orig_y);
    menu->x_pos = orig_x;	/* Store X and Y coords of menu. */
    menu->y_pos = orig_y;

    if (XMenuRecompute(display, menu) == XM_FAILURE) {
	return(XM_FAILURE);
    }

    /*
     * Flush the window creation queue.
     * This batches all window creates since lazy evaluation
     * is more efficient than individual evaluation.
     * This routine also does an XFlush().
     */
    if (_XMWinQueFlush(display, menu, cur_p, cur_s) == _FAILURE) {
	return(XM_FAILURE);
    }

    /*
     * Make sure windows are in correct order (in case we were passed
     * an already created menu in incorrect order.)
     */
    for(p_ptr = menu->p_list->next; p_ptr != cur_p; p_ptr = p_ptr->next)
	XRaiseWindow(display, p_ptr->window);
    for(p_ptr = menu->p_list->prev; p_ptr != cur_p->prev; p_ptr = p_ptr->prev)
	XRaiseWindow(display, p_ptr->window);

    /*
     * Make sure all selection windows are mapped.
     */
    for (
	p_ptr = menu->p_list->next;
	p_ptr != menu->p_list;
	p_ptr = p_ptr->next
    ){
	XMapSubwindows(display, p_ptr->window);
    }

    /*
     * Synchronize the X buffers and the event queue.
     * From here on, all events in the queue that don't belong to
     * XMenu are sent back to the application via an application
     * provided event handler or discarded if the application has
     * not provided an event handler.
     */
    XSync(display, 0);

    /*
     * Grab the mouse for menu input.
     */

    status = XGrabPointer(
			  display,
			  menu->parent,
			  True,
			  event_mask,
			  GrabModeAsync,
			  GrabModeAsync,
			  None,
			  menu->mouse_cursor,
			  CurrentTime
			  );
    if (status == Success && x_menu_grab_keyboard)
      {
        status = XGrabKeyboard (display,
                                menu->parent,
                                False,
                                GrabModeAsync,
                                GrabModeAsync,
                                CurrentTime);
        if (status != Success)
          XUngrabPointer(display, CurrentTime);
      }

    if (status == _X_FAILURE) {
	_XMErrorCode = XME_GRAB_MOUSE;
	return(XM_FAILURE);
    }

    /*
     * Map the menu panes.
     */
    XMapWindow(display, cur_p->window);
    for (p_ptr = menu->p_list->next;
	 p_ptr != cur_p;
	 p_ptr = p_ptr->next)
      XMapWindow(display, p_ptr->window);
    for (p_ptr = cur_p->next;
	 p_ptr != menu->p_list;
	 p_ptr = p_ptr->next)
      XMapWindow(display, p_ptr->window);

    XRaiseWindow(display, cur_p->window);	/* Make sure current */
						/* pane is on top. */

    cur_s = NULL;			/* Clear current selection. */

    /*
     * Begin event processing loop.
     */
    while (1) {
        if (wait_func) (*wait_func) (wait_data);
	XNextEvent(display, &event);	/* Get next event. */
	switch (event.type) {		/* Dispatch on the event type. */
    case Expose:
	    event_xmp = (XMPane *)XLookUpAssoc(display,
					       menu->assoc_tab,
					       event.xexpose.window);
	    if (event_xmp == NULL) {
		/*
		 * If AEQ mode is enabled then queue the event.
		 */
		if (menu->aeq) {
		    feq_tmp = (XMEventQue *)malloc(sizeof(XMEventQue));
		    if (feq_tmp == NULL) {
			_XMErrorCode = XME_CALLOC;
			return(XM_FAILURE);
		    }
		    feq_tmp->event = event;
		    feq_tmp->next = feq;
		    feq = feq_tmp;
		}
		else if (_XMEventHandler) (*_XMEventHandler)(&event);
		break;
	    }
	    if (event_xmp->activated) {
		XSetWindowBackground(display,
				     event_xmp->window,
				     menu->bkgnd_color);
	    }
	    else {
		XSetWindowBackgroundPixmap(display,
					   event_xmp->window,
					   menu->inact_pixmap);
	    }
	    _XMRefreshPane(display, menu, event_xmp);
	    break;
    case EnterNotify:
	    /*
	     * First wait a small period of time, and see
	     * if another EnterNotify event follows hard on the
	     * heels of this one. i.e., the user is simply
	     * "passing through". If so, ignore this one.
	     */

	    event_xmw = (XMWindow *)XLookUpAssoc(display,
						 menu->assoc_tab,
						 event.xcrossing.window);
	    if (event_xmw == NULL) break;
	    if (event_xmw->type == SELECTION) {
		/*
		 * We have entered a selection.
		 */
		/* if (XPending(display) == 0) usleep(150000); */
		if (XPending(display) != 0) {
		    XPeekEvent(display, &peek_event);
		    if(peek_event.type == LeaveNotify) {
			break;
		    }
		}
		cur_s = (XMSelect *)event_xmw;
		help_callback (cur_s->help_string,
			       cur_p->serial, cur_s->serial);

		/*
		 * If the pane we are in is active and the
		 * selection entered is active then activate
		 * the selection.
		 */
		if (cur_p->active && cur_s->active > 0) {
		    cur_s->activated = 1;
		    _XMRefreshSelection(display, menu, cur_s);
		}
	    }
	    else {
		/*
		 * We have entered a pane.
		 */
		/* if (XPending(display) == 0) usleep(150000); */
		if (XPending(display) != 0) {
		    XPeekEvent(display, &peek_event);
		    if (peek_event.type == EnterNotify) break;
		}
		XQueryPointer(display,
			      menu->parent,
			      &root, &child,
			      &root_x, &root_y,
			      &win_x, &win_y,
			      &mask);
		event_xmp = (XMPane *)XLookUpAssoc(display,
						   menu->assoc_tab,
						   child);
		if (event_xmp == NULL) break;
		if (event_xmp == cur_p) break;
		if (event_xmp->serial > cur_p->serial) forward = True;
		else forward = False;
		p_ptr = cur_p;
		while (p_ptr != event_xmp) {
		    if (forward) p_ptr = p_ptr->next;
		    else p_ptr = p_ptr->prev;
		    XRaiseWindow(display, p_ptr->window);
		}
		if (cur_p->activated) {
		    cur_p->activated = False;
		    XSetWindowBackgroundPixmap(display,
					       cur_p->window,
					       menu->inact_pixmap);
		    _XMRefreshPane(display, menu, cur_p);
		}
		if (event_xmp->active) event_xmp->activated = True;
#if 1
		/*
		 * i suspect the we don't get an EXPOSE event when backing
		 * store is enabled; the menu windows content is probably
		 * not drawn in when it should be in that case.
		 * in that case, this is probably an ugly fix!
		 * i hope someone more familiar with this code would
		 * take it from here.  -- caveh@eng.sun.com.
		 */
		XSetWindowBackground(display,
				     event_xmp->window,
				     menu->bkgnd_color);
		_XMRefreshPane(display, menu, event_xmp);
#endif
		cur_p = event_xmp;
	    }
	    break;
    case LeaveNotify:
	    event_xmw = (XMWindow *)XLookUpAssoc(
						 display,
						 menu->assoc_tab,
						 event.xcrossing.window
						 );
	    if (event_xmw == NULL) break;
	    if(cur_s == NULL) break;

	    /*
	     * If the current selection was activated then
	     * deactivate it.
	     */
	    /* Emacs specific, HELP_STRING cannot be validly NULL
	     * in the real XMenu library.  */
	    help_callback (NULL, cur_p->serial, cur_s->serial);
	    if (cur_s->activated) {
		cur_s->activated = False;
		_XMRefreshSelection(display, menu, cur_s);
	    }
	    cur_s = NULL;
	    break;

    case ButtonPress:
    case ButtonRelease:
		*p_num = cur_p->serial;
		/*
		 * Check to see if there is a current selection.
		 */
		if (cur_s != NULL) {
		    /*
		     * Set the selection number to the current selection.
		     */
		    *s_num = cur_s->serial;
		    /*
		     * If the current selection was activated then
		     * we have a valid selection otherwise we have
		     * an inactive selection.
		     */
		    if (cur_s->activated) {
			*data = cur_s->data;
			ret_val = XM_SUCCESS;
		    }
		    else {
			ret_val = XM_IA_SELECT;
		    }
		}
		else {
		    /*
		     * No selection was current.
		     */
		    ret_val = XM_NO_SELECT;
		}
		selection = True;
		break;
        case KeyPress:
        case KeyRelease:
                keysym = XLookupKeysym (&event.xkey, 0);

                /* Pop down on C-g and Escape.  */
                if ((keysym == XK_g && (event.xkey.state & ControlMask) != 0)
                    || keysym == XK_Escape) /* Any escape, ignore modifiers.  */
                  {
                    ret_val = XM_NO_SELECT;
                    selection = True;
                  }
               break;
	    default:
		/*
		 * If AEQ mode is enabled then queue the event.
		 */
		if (menu->aeq) {
		    feq_tmp = (XMEventQue *)malloc(sizeof(XMEventQue));
		    if (feq_tmp == NULL) {
			_XMErrorCode = XME_CALLOC;
			return(XM_FAILURE);
		    }
		    feq_tmp->event = event;
		    feq_tmp->next = feq;
		    feq = feq_tmp;
		}
		else if (_XMEventHandler) (*_XMEventHandler)(&event);
		break;
#ifdef HAVE_XINPUT2
        case GenericEvent:
	    if (translate_func)
	      translate_func (&event);
#endif
	}
	/*
	 * If a selection has been made, break out of the event loop.
	 */
	if (selection == True) break;
    }

    /*
     * Unmap the menu.
     */
    for ( p_ptr = menu->p_list->next;
	 p_ptr != menu->p_list;
	 p_ptr = p_ptr->next)
      {
	  XUnmapWindow(display, p_ptr->window);
      }

    /*
     * Ungrab the mouse.
     */
    XUngrabPointer(display, CurrentTime);
    XUngrabKeyboard(display, CurrentTime);

    /*
     * Restore bits under where the menu was if we managed
     * to save them and free the pixmap.
     */

    /*
     * If there is a current selection deactivate it.
     */
    if (cur_s != NULL) cur_s->activated = 0;

    /*
     * Deactivate the current pane.
     */
    cur_p->activated = 0;
    XSetWindowBackgroundPixmap(display, cur_p->window, menu->inact_pixmap);

    /*
     * Synchronize the X buffers and the X event queue.
     */
    XSync(display, 0);

    /*
     * Dispatch any events remaining on the queue.
     */
    while (QLength(display)) {
	/*
	 * Fetch the next event.
	 */
	XNextEvent(display, &event);

	/*
	 * Discard any events left on the queue that belong to XMenu.
	 * All others are held and then returned to the event queue.
	 */
	switch (event.type) {
	    case Expose:
	    case EnterNotify:
	    case LeaveNotify:
	    case ButtonPress:
	    case ButtonRelease:
		/*
		 * Does this event belong to one of XMenu's windows?
		 * If so, discard it and process the next event.
		 * If not fall through and treat it as a foreign event.
		 */
		event_xmp = (XMPane *)XLookUpAssoc(
						   display,
						   menu->assoc_tab,
						   event.xbutton.window
						   );
		if (event_xmp != NULL) continue;
		FALLTHROUGH;
	    default:
		/*
		 * This is a foreign event.
		 * Queue it for later return to the X event queue.
		 */
		feq_tmp = (XMEventQue *)malloc(sizeof(XMEventQue));
		if (feq_tmp == NULL) {
		    _XMErrorCode = XME_CALLOC;
		    return(XM_FAILURE);
		}
		feq_tmp->event = event;
		feq_tmp->next = feq;
		feq = feq_tmp;
	    }
    }
    /*
     * Return any foreign events that were queued to the X event queue.
     */
    while (feq != NULL) {
	feq_tmp = feq;
	XPutBackEvent(display, &feq_tmp->event);
	feq = feq_tmp->next;
	free((char *)feq_tmp);
    }

    wait_func = 0;

    /*
     * Return successfully.
     */
    _XMErrorCode = XME_NO_ERROR;
    return(ret_val);

}
